Pleistocene Ice Volumes and Sea-Level Lowering

Based upon recent investigations of existing and of Pleistocene ice sheets, revised estimates of late Pleistocene ice volumes and resulting pea-level lowering are made. The thickness of Pleistocene ice sheets has been determined by applying the thickness-area ratio of existing ice sheets to the revised areas of the past ice sheets. Revised values are given for the Classical Wisconsin (less than 30,000 years B.P.), early Wisconsin (greater than 30,000 years B.P.), and the Illinoian (third) glacial stages which are here considered equivalent to the Weichsel, Warthe, and Saale stages, respectively. The Illinoian is shown to be the stage of maximum glaciation with consequent sea-level decrease about 50 per cent greater than that usually given for the Wisconsin. This lower stand of the sea is well shown by recent submarine exploration.